Kraft is removing artificial preservatives from its most popular Singles cheese product variety, in the latest sign that companies are tweaking recipes as food labels come under greater scrutiny.

The change affects the company's Kraft Singles in the full-fat American and White American varieties, which Kraft says account for the majority of the brand's sales. Sorbic acid is being replaced by natamycin, which Kraft says is a "natural mold inhibitor."

Kraft's decision comes as a growing number of Americans pay closer attention to what they eat and try to stick to foods they feel are natural. That has prompted a number of food makers to change their recipes.

Last week, for instance, Subway said it was removing a chemical from its bread after a popular food blogger named Vani Hari started a petition noting the ingredient is also used in yoga mats.

The ingredient, azodicarbonamide, is an approved food additive and can be found in a wide variety of products, including those sold by McDonald's and Starbucks. But Hari said she targeted Subway because of its healthy food image.

Even though such ingredients are approved for use by the Food and Drug Administration, being able to tout a product as being free of them can be a selling point. Kraft, for example, plans to begin airing TV ads near the end of February touting that its Kraft Singles cheese product "begins with milk" and are now "made with no artificial preservatives."

The ads show cartoon cows grazing in a pasture, with a milk truck driving past.

The new Kraft packages, which began appearing on supermarket shelves in recent weeks, also come stamped with a red circle noting they have no artificial preservatives or flavors. Kraft says its Singles haven't used artificial flavors for many years, but that it just recently decided to advertise that aspect of the product.

"Consumers are looking for those less artificial cues and messages," said Gavin Schmidt, manager of cheese research and development at Kraft. "Those messages are more meaningful to consumers than they have been in the past."

Schmidt says the change took about five years to perfect because Kraft wanted to ensure the product's taste and shelf life remained the same. He declined to provide details, but said it wasn't as simple as swapping out an artificial preservative and replacing it with a natural one.

"There's a little more to it than that," he said.

Schmidt said Kraft is testing the removal of artificial preservatives from its other Kraft Singles varieties, but that it wanted to start with the most popular lines first. The changes do not affect Kraft Singles that are 2 percent milk, fat-free or other full-fat varieties.

Kraft Foods Group Inc., based in Northfield, Ill., also makes brands including Oscar Mayer, Jell-O, Planters and Maxwell House.